High-Efficiency Targeted Modification Of Plant Genomes Using Engineered Endonucleases

Recent advances in high-efficiency methods for targeted genome modification have equipped plant biologists with another powerful genetic tool to facilitate understanding gene functions and expedite translational research to develop crop varieties with higher productivity, enhanced nutrition and lower input costs.  Efficient genome modifications often require targeted cleavage of specific chromosomal sequences, which generates double strand DNA breaks (DSBs) and activates endogenous DNA repair pathways.  Cellectis has developed platforms to design and generate highly specific and active endonucleases, known as meganucleases, and more recently, TALE nucleases (TALENs), for recognizing and cleaving desired DNA sequences.  The reagents and delivery methods have been optimized to achieve highly efficient targeted mutagenesis in a number of plant species, including rice, soybean and tobacco.  Such high efficiencies make it possible to recover genome modifications even without selection or enrichment regimes.  As the results, our technology opens the door to make targeted genome modification of plants a routine practice and promises to facilitate creation of new crop varieties to meet burgeoning agricultural demands.  Moreover, the potential impact of targeted genome engineering technology on regulatory decisions will also be presented.